Surface topography and light scattering were measured on 15 samples ranging from those having smooth surfaces to others with ground surfaces. The measurement techniques included an atomic force microscope, mechanical optical profilers, confocal laser scanning angle-resolved scattering, total scattering. polished fused silica, silicon carbide, sapphire, electroplated gold, diamond-turned brass. instruments had different surface spatial wavelength band limits, so the roughnesses not directly...

Toward a Smart Optical Biosensor Based on Nanoporous Anodic Alumina (NAA): By modifying the pore geometry in nanoporous anodic alumina we are able to change effective medium at will and tune photoluminescence of NAA. The oscillations PL spectrum converted into exclusive barcodes, which useful for developing optical biomedical sensors UV-Visible region. Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...

In this study, we report about the structural engineering and optical optimization of nanoporous anodic alumina rugate filters (NAA-RFs) for real-time label-free biosensing applications. Structurally engineered NAA-RFs are combined with reflection spectroscopy (RfS) in order to develop a system based on position shift characteristic peak spectrum (Δλpeak). This is optimized assessed by measuring shifts produced small changes effective medium (i.e., refractive index). To end, filled different...

A cost-effective label-free optical biosensor based on gold-coated self-ordered nanoporous anodic alumina bilayers is presented. The structure formed by two uniform layers of different porosity (i.e., a top layer with large pores and bottom smaller pores). Each presents pore size, regular distribution, diameter along its length. To increase improve the output sensing signals, thin gold surface was deposited. increases refractive index contrast between analytical aqueous solution, it results...

Modern-day wonders of the world: Nanostructured films plasmonic pyramid arrays (see picture) were prepared by simple stamping preformed homogeneous nanocolloids. These materials show very high efficiency as optical enhancers and can be exploited for design quantitative, cheap, portable, ultrasensitive sensors with excellent reversibility. The fabrication macroscale from nanoscale building blocks is focus much current multidisciplinary research. In these macromaterials, properties are...

Herein, we present a smart enzymatic sensor based on nanoporous anodic alumina (NAA) and its photoluminescence (PL) in the UV–visible range. The as-produced structure of NAA is functionalized activated order to perform enzyme immobilization controlled manner. whole process monitored through PL spectrum each stage characterized by an exclusive barcode, which associated with oscillations. This characteristic property allows us calculate change effective optical thickness that takes place after...

Herein, we present an ultrasensitive, cost-competitive, and portable optical sensing system for detecting ionic mercury in environmental water. This analytical combines structurally engineered chemically modified nanoporous anodic alumina rugate filters (NAA-RFs) with reflection spectroscopy (RfS). The performance of the proposed is assessed through several tests, establishing its (i.e., linear working range from 1 to 100 μM Hg2+, low limit detection Hg2+ ions 200 ppb), sensitivity 0.072 nm...

The dark current-voltage characteristics of poly (3-hexylthiophene) (P3HT)/n-type crystalline silicon solar cells were analyzed using an electrical equivalent circuit. We found that without illumination transport occurs due to hopping between localized states at the P3HT/silicon interface not only low voltages, through multitunneling capture emission, but also medium tunneling-enhanced recombination. At high voltages current is limited by series resistance and space-charge mechanisms....

In this study, we demonstrate that an optimal design of the pore geometry and shape sensing platforms based on nanoporous anodic alumina (NAA) photonic structures is critical to develop optical sensors with improved capabilities. To end, two types NAA featuring different geometries (i.e., lengths diameters) shapes straight modulated pores) were produced, their characteristics assessed systematically by reflectometric interference spectroscopy. The geometric features lengths, diameters,...

A distributed Bragg reflector based on nanoporous anodic alumina was fabricated using an innovative cyclic anodization voltage approach, which resulted in in-depth modulation of the pore geometry and refractive index. The effect a pore-widening wet-etching step structure's photonic stop-band properties studied. From transmittance measurements, it shown that by changing time is possible to modulate stop band range visible near infrared. With help theoretical model, we were able obtain...

Controlled drug delivery systems are an encouraging solution to some disadvantages such as reduced solubility, deprived biodistribution, tissue damage, fast breakdown of the drug, cytotoxicity, or side effects. Self-ordered nanoporous anodic alumina is auspicious material for due its biocompatibility, stability, and controllable pore geometry. Its use in applications has been explored several fields, including therapeutic devices bone dental engineering, coronary stent implants, carriers...

This study presents the development and optical engineering of stacked nanoporous anodic alumina gradient-index (NAA-GIFs) filters with tunable multispectral photonic stopbands for sensing applications. The structure these crystals (PC) is formed by layers NAA produced sinusoidally modified effective medium. progressive modification sinusoidal period during anodization process enables generation precise tuning characteristic (PSB) (i.e., one per in profile) PC structures. Four types NAA-GIFs...

The chemical modification, or functionalization, of the surfaces nanomaterials is a key step to achieve biosensors with best sensitivity and selectivity. surface modification usually comprises several steps that have be optimized. Real-time monitoring all reactions taking place during such can highly helpful tool for optimization. In this work, we propose nanoporous anodic alumina (NAA) functionalized streptavidin-biotin complex as platform towards label-free biosensors. Using reflective...

Human growth hormone (hGH) is a polypeptide that synthesized and secreted by the anterior pituitary gland, whose excess linked to acromegaly-causing adenomas while deficiencies are disorders including short stature Turner’s syndrome. This study investigates real-time biosensing of hGH using microfluidic optical biosensor based on reflectometric interferometry Fourier spectroscopy (RIFTS). The platform monolayer nanoporous anodic alumina (NAA) fabricated following two-step anodization method...

Single layers of MgF2 and LaF3 were deposited upon superpolished fused-silica CaF2 substrates by ion-beam sputtering (IBS) as well boat electron beam (e-beam) evaporation characterized a variety complementary analytical techniques. Besides undergoing photometric ellipsometric inspection, the samples investigated at 193 633 nm an optical scatter measurement facility. The structural properties assessed with atomic-force microscopy, x-ray diffraction, TEM techniques that involved conventional...

Abstract We report on an exhaustive and systematic study about the photoluminescent properties of nanoporous anodic alumina membranes fabricated by one-step anodization process under hard conditions in oxalic malonic acids. This optical property is analysed as a function several parameters (i.e. voltage, pore diameter, membrane thickness, annealing temperature acid electrolyte). analysis makes it possible to tune behaviour at will simply modifying structural characteristics these membranes....

A detailed study of the pore-widening rate nanoporous anodic alumina layers as a function anodization voltage was carried out. The focuses on samples produced under same electrolyte and concentration but different voltages within self-ordering regime. By means ellipsometry-based optical characterization, it is shown that in porewidening process, porosity increases at faster for lower voltages. This opens possibility obtaining three-dimensional nanostructured with controlled thickness...

In this paper, we demonstrate that zinc oxide (ZnO) layers deposited by inkjet printing (IJP) can be successfully applied to the low-temperature fabrication of efficient inverted polymer solar cells (i-PSCs). The effects ZnO IJP as electron transport layer (ETL) on performance i-PSCs based PTB7-Th:PC70BM active are investigated. morphology ZnO-IJP was analysed AFM, and compared different techniques. study shows underlayer has a dramatic effect band structure non-geminate recombination...

Bi2S3 nanocrystals with different shapes and sizes are obtained by a hot injection approach using bismuth neodecanoate thiolamine as sulfur precursors. The colloid morphology, from nanodots to nanorods, ranging 3–4 nm 40–50 strongly depends on the preparation conditions such temperature ratio of Bi/S precursors ultimately impacts optical electrical properties final nanocrystals. resulting products analyzed X-ray powder diffraction (XRD), transmission electron microscope (TEM), UV–vis...